There are multiple very relevant threats which survive Lightning Bolt but die to Heat, such as [card]Yawgmoth, Thran Physician, Omnath, Locus of Creation, Crashing Footfalls, Primeval Titan, most Planeswalkers, Yorion, Sky Nomad, and the list goes on
This, combined with the player count having dropped by around 50% since the game's launch (according to estimates from ActivePlayer), and interested players only being able to get a single copy of the card as part of their purchase, makes shiny Mewtwo ex the rarest Pokemon TCG Pocket promo card of all time
This means there are, supposedly, 15 total copies of these cards in circulation, or 5 each of the first, second, and third-place variants
OP-16 Admiral Manga Rares (Sakazuki, Kuzan, Borsalino) are collector trophies, not meta cards
This Call of Legends Staff Prerelease Snorlax offers an unusual depiction of this Pokemon that feels even darker than its appearance in ex Team Rocket Returns